#include "args.hh" #include "hash.hh" namespace nix { void Args::parseCmdline(const Strings & _cmdline) { Strings pendingArgs; bool dashDash = false; Strings cmdline(_cmdline); for (auto pos = cmdline.begin(); pos != cmdline.end(); ) { auto arg = *pos; /* Expand compound dash options (i.e., `-qlf' -> `-q -l -f', `-j3` -> `-j 3`). */ if (!dashDash && arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && isalpha(arg[1])) { *pos = (string) "-" + arg[1]; auto next = pos; ++next; for (unsigned int j = 2; j < arg.length(); j++) if (isalpha(arg[j])) cmdline.insert(next, (string) "-" + arg[j]); else { cmdline.insert(next, string(arg, j)); break; } arg = *pos; } if (!dashDash && arg == "--") { dashDash = true; ++pos; } else if (!dashDash && std::string(arg, 0, 1) == "-") { if (!processFlag(pos, cmdline.end())) throw UsageError(format("unrecognised flag ‘%1%’") % arg); } else { pendingArgs.push_back(*pos++); if (processArgs(pendingArgs, false)) pendingArgs.clear(); } } processArgs(pendingArgs, true); } void Args::printHelp(const string & programName, std::ostream & out) { std::cout << "Usage: " << programName << " <FLAGS>..."; for (auto & exp : expectedArgs) { std::cout << renderLabels({exp.label}); // FIXME: handle arity > 1 if (exp.arity == 0) std::cout << "..."; } std::cout << "\n"; auto s = description(); if (s != "") std::cout << "\nSummary: " << s << ".\n"; if (longFlags.size()) { std::cout << "\n"; std::cout << "Flags:\n"; printFlags(out); } } void Args::printFlags(std::ostream & out) { Table2 table; for (auto & flags : longFlags) table.push_back(std::make_pair( "--" + flags.first + renderLabels(flags.second.labels), flags.second.description)); printTable(out, table); } bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) { assert(pos != end); auto process = [&](const std::string & name, const Flag & flag) -> bool { ++pos; Strings args; for (size_t n = 0 ; n < flag.arity; ++n) { if (pos == end) throw UsageError(format("flag ‘%1%’ requires %2% argument(s)") % name % flag.arity); args.push_back(*pos++); } flag.handler(args); return true; }; if (string(*pos, 0, 2) == "--") { auto i = longFlags.find(string(*pos, 2)); if (i == longFlags.end()) return false; return process("--" + i->first, i->second); } if (string(*pos, 0, 1) == "-" && pos->size() == 2) { auto c = (*pos)[1]; auto i = shortFlags.find(c); if (i == shortFlags.end()) return false; return process(std::string("-") + c, i->second); } return false; } bool Args::processArgs(const Strings & args, bool finish) { if (expectedArgs.empty()) { if (!args.empty()) throw UsageError(format("unexpected argument ‘%1%’") % args.front()); return true; } auto & exp = expectedArgs.front(); bool res = false; if ((exp.arity == 0 && finish) || (exp.arity > 0 && args.size() == exp.arity)) { exp.handler(args); expectedArgs.pop_front(); res = true; } if (finish && !expectedArgs.empty()) throw UsageError("more arguments are required"); return res; } void Args::mkHashTypeFlag(const std::string & name, HashType * ht) { mkFlag1(0, name, "TYPE", "hash algorithm (‘md5’, ‘sha1’, ‘sha256’, or ‘sha512’)", [=](std::string s) { *ht = parseHashType(s); if (*ht == htUnknown) throw UsageError(format("unknown hash type ‘%1%’") % s); }); } Strings argvToStrings(int argc, char * * argv) { Strings args; argc--; argv++; while (argc--) args.push_back(*argv++); return args; } std::string renderLabels(const Strings & labels) { std::string res; for (auto label : labels) { for (auto & c : label) c = std::toupper(c); res += " <" + label + ">"; } return res; } void printTable(std::ostream & out, const Table2 & table) { size_t max = 0; for (auto & row : table) max = std::max(max, row.first.size()); for (auto & row : table) { out << " " << row.first << std::string(max - row.first.size() + 2, ' ') << row.second << "\n"; } } }